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A case of unilateral congenitally enlarged extraocular muscles
J S Dickson1, S P Kraft, V Jay
1Department of Ophthalmology, Hospital for Sick Children, Toronto, Ontario, Canada.
Insights
Congenital unilateral enlargement of extraocular muscles in an infant was investigated. Despite imaging and biopsy, the cause of this rare condition remains unknown, presenting a unique clinical case.
Area of Science:
- Ophthalmology
- Pediatric Neurology
- Medical Imaging
Background:
- Enlargement of extraocular muscles is a rare pediatric finding.
- Limited literature exists on the causes of congenital extraocular muscle enlargement.
Observation:
- A case study of an 8-month-old girl with unilateral congenital enlarged extraocular muscles.
- Clinical presentation included nonprogressive left esotropia and hypotropia at birth.
Findings:
- Computed tomography (CT) and magnetic resonance imaging (MRI) revealed enlarged left inferior, lateral, and medial rectus muscles.
- Intraoperative forced duction testing showed muscle restriction, but macroscopic appearance was normal.
- Histologic, histochemical, and electron microscopic studies of the lateral rectus muscle biopsy yielded no pathological findings.
Implications:
- This case presents a unique constellation of findings not matching previously reported patterns of extraocular muscle enlargement.
- Further research is needed to understand the etiology of such rare pediatric ophthalmological conditions.
Background:
Enlargement of extraocular muscles is an uncommon finding in children. Little has been written in the literature about possible causes.
Methods:
The authors present the clinical findings of a young girl who had unilateral congenitally enlarged extraocular muscles at 8 months of age. She underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans, systemic assessment, and extraocular muscle biopsy to determine a cause for the enlarged muscles.
Results:
The patient had a unilateral left esotropia and hypotropia at birth that was nonprogressive. High-resolution CT and MRI scans showed enlargement of the left inferior rectus, lateral rectus, and medial rectus muscles. Strabismus surgery undertaken at 2 years of age showed that the affected muscles were restricted on forced duction testing but were macroscopically normal in appearance. A biopsy specimen of the left lateral rectus muscle was processed for histologic, histochemical, and electron microscopic studies, but no abnormal pathologic findings were found.
Conclusion:
This patient's constellation of findings appears to be unique: it does not follow any previously reported pattern of disorders of extraocular muscle enlargement.